Adjustable slice for flow box



March 1960 A. w. WESTERN ETAL 2,928,464

ADJUSTABLE SLICE FOR FLOW BOX 3 Sheets-Sheet 1 Filed Dec. 24, 1957iibihi i O O I o Qua/9.;

rllllllll 611%! Gardner Attorneys March 15, 1960 A. w. WESTERN ET AL 2,2

ADJUSTABLE SLICE FOR FLOW BOX 3 Sheets-Sheet 2 Filed Dec. 24, 1957dim/ll gm-lea V y m Attorneys March 15, 1960 A. w. WESTERN ET AL2,928,464

ADJUSTABLE s LIcE FOR FLOW BOX 5 Sheets-Sheet 3 Filed Dec. 24, 1957.Q..; I J 5 22 6 A// w w v Q United Sta Patmtl O ADJUSTABLE SLICE FORFLOW BOX Arthur William Western and Roland C. Gardner, Aylesford, nearMaidstone, England, assignors to Albert E. Reed and Company Limited,London, England, a British company Application December 24, 1957, SerialNo. 704,967

Claims priority, application Great Britain January 1, 1957 Claims. (Cl.162-347) This invention is concerned withimprovements in or relating tothe manufacture of paper, board or like fibrous products and moreparticularly with machines and parts thereof for the manufacture ofpaper, board or like fibrous products.

' It is usual in paper or board machines to have mechanical meanswhereby the top slice lip of the flow box can be deformed across itswidth in order to vary the size of the aperture at different parts ofits length so as to control the quantity or density of the stuff flowingout of the flow box onto the wire. Such control is required not only tocounteract the sag which occurs across the width of the top slice lip ina large machine, but also to take account of eddies and non-uniform flowwithin the flow box. It is furthermore often desired to vary the flow ofstuff onto the wire across its width to take into account the nonuniform shrinkage of the web ondrying.

Deformation of the top slice lip'is effected in known machines bymechanical means which include a plurality of rods connected to the toplip and provided with threaded adjusting means by which selected rodscan be raised or lowered to change the profile of the top lip. There arevarious disadvantages to this means of varying the profile of the topslice lip. The space required to mount and manipulate the threadedadjusting means, which are usually handwheels, places a limit on howclose together the rods can be located and therefore on the amount ofcontrol which is exercisable. The connection of a rod to the lip meansthat tension or pressure is exerted substantially at a point with aconsequent tendency to produce abrupt changes in the profile of the lip.A superstructure has to be provided on the front of the flow box tocarry the adjusting means, and in large machines a runway is required toenable a machine man to have access to the handwheels to make anynecessary adjustments. Variations in the profile of the top lipcouldonly be effected remotely from the machine by means of a verycomplex and cumbersome linkage which would be quite impracticable.Furthermore with any threaded mechanism subjected to the workingconditions of a paper or board machine backlash in the transmissionagain reduces the degree of control.

In addition where a paper or board machine is used having a top wire inaddition to the normal wire, it may .be desirable that the slice shallfeed the stuff as nearly as possible into the nip between the two wires.Mechanical control of the above mentioned kind is impossible if that isto be achieved since the closer to the nip the slice is disposed, theless space is there for the top lip adjusting mechanism.

' It is one object of this invention to provide improved means forvarying the profile of the slice of a flow box in a paper or boardmachine, which overcomes the above mentioned disadvantages and enablesthe slice to be easily controlled if desired remotely from the machinewithout the need for cumbersome mechanical transmissrons.

According to. the invention we provide a slice for the flow box of apaper or board machine in which the top and/or bottom lip is providedwith one. or a plurality of flexible, fluid impervious bags, capsules,or equivalent closed chamber devices extending across its length andbearing directly or indirectly uponit, said bag(s) or capsulets) beingadapted to be filled with fluid and means for varying the fluid pressurein said bag or capsule or any of them in order to vary the profile ofthelip.

Whilst we may employ a single bag or capsule extending wholly orpartially across the lip, we prefer to provide a plurality of small.bags or capsules disposed close to one another across the slice lipsincebyvarying the fluid pressure in the individual bags across theslice lip a finer control on its profile can be exercised than is thecase with a single bag.

The bags or capsules may be of, rubber, polyethylene, polyvinyl chlorideor any other suitable substance which is flexible so as to transmitfluid. pressure and impervious to the fluid to be used. In general weprefer to use a liquid in the bags or capsules such as oilfor water,although with appropriate means for pressure control a gas could beused. V

The bags or capsules may be of any desired shape. In general we havefound it convenient to have them of generally rectangular shape and ofthe same size across the slice lip. If, however, it is desired to beable to exercise greater pressures and thus larger deformations at anypart of the slice 'lip, we may have bags orcapsules of appropriateshapes and sizes, since it will be understood that by increasing thearea of contact of the bag with the slice lip at any part thereofgreater pressure will be exerted on that part of the lip for a givenincrease inthe fluid pressure and hence a greater deformation will beeffected. If desired individual bags or capsules may be made of varyingwidths over their length so,that varying applications of pressuremay beobtained. Similarly the wall thicknesses of the bags or capsules may bevaried if desired.

In order to localise or concentrate the application of pressure withinthe bags to the slice lip, we prefer to provide the bags or capsuleswith side walls which are thicker than their pressure applying surfacesor alternatively to provide pockets or seatings within the slice lipstructure, which pockets or seatings receive the bags snugly side of theslice lip arestaggered with respect to each other.

Each bag or capsule or other closed chamber device is connected to meanssuch as a bellows or pump whereby the fluid pressure in it can be variedas required, we may however, provide a further bellows or pump soconnected to the closed fluid systems of the individual bags as toenable a common pressure variation to be imposed upon them all.

The lip of the slice to be deformed is formed of any suitable resilientmaterial, for instance stainless steel-of a suitable degree offlexibility or spring steel suitably coated to resist corrosion and isso mounted in a support that it will be constrained to bear against thesupport thus giving a'precise starting'position from which it can bedeformed as required. This may be achieved by gripping the slice lipbetween two rigid supporting plates, .one of Patented Mar. 15, 1960slice hp 5.

disposed with their pressureapplying surfaces between the. supportingplate and the slice lip so that pressure'variaa tions appli'ed tothe fluid will be directly trans'ng ittedr'to the lip to cause itsdeformation.

' s ms as. will be. seen from Fig. 2 the, pipes24. leading. the capsules25 in the'top'supporting plate 7 are grouped together and led'along thefrontwall of the flow box 4.

' They are retained in position by securing straps 28 and at In orderthat the invention may bewell understood,

one preferred; embodiment only thereof by way of ex ample will bedescribed in furtherdetail with reference to the accompanying drawingsin which:

Figure l is a'diagrammatic side view of the wet end of a paper makingmachine showing the wire and a flowbox having top andbottom slice lipsaccording to the invention,

Figure 2 s a front view of a part only of the flow box one side of theflow bo rare led oif to a control panel 29 which carries one pressurecontrolling bellows 27 for each capsule. Thefiuid inlet pipes for thebottom slice lip which are not [shown are similarly grouped together andeach lead to a pressure controlling bellows inrthe control panel 29. a v

The control panel 29 which is disposed at anyl cation convenient to anoperatorhouses all the bellows units 27 of Figure-l with the cover plateremoved and'showing '1' henceithe PICSSUIG'QfflEh} fluid therein can beclosely the arrangement ofpipesfroht the capsules-tothe control panel,"1 a .1 a a Figure 3 is-an e'nlargedside sectional View of the top andbottom slice lips of Figure'l, Figure 4 is a section onthe line Figure5; is an underneath plan view of the supporting;

plate of the top slice lipof Figure l, and a Figure 6 is a sectionalview on the line VI'VI of Fig 2 and shows one of thepressure'applyingunits in the control panel. v Referring to Figure 1there is shown diagrammatically part of the'we t endfof a'Fourdrinieri-paper making; machine. v a a The wire 1 passes around abreast roll 2 and table. rollers 3 and beneath a flow box 4, from whichstock is supplied to the wire for the production of paper in a generallyknown manner.

The flow'box 4 has a top slice lip 5 and a bottom slice lip 6 whichextend across the whole width of theflow box. The top slice lip 5 iscarried, by a' supporting plate 7 which is rigidly secured to the frontwall 8 ,of the flow box." This front wall 8 is -so mounted to-the flowbok'that it can be raised or lowered with respect .to the remainder ofthe flow box by means of bevel gears 9 and hand wheel'10' in ordercontrolled. I

Each unit consisting, of a capsule its inlet piper24 required therebeing one such bellows 28 for'each capsule 25 provided on the topandbottom slice lips. As will seen from Figure 6the bellows 27 is a closedcompressible bellows unit known perse having a hand wheel .by

which the compression or expansion of the bellows and e and associatedbellows 27 constitutes a closed system and; is filled with asuitablefluid, e. g. oil or water. It isthuat, possible selectively tovary the pressure of each capsule along the length of either slice lip 5or 6.

Itwill be appreciatedthat when it is desired to vary the? ;.profile ofeither slice lip during'operation of the paper on board machine it ismerely necessary to raise or lower the pressure in one or more ofthebags or capsules 25in to vary the space *betwenthetop and bottomslicelips. The bottom slice lip 6 is carried by a supporting plate I 11 issubstantially identical. j a a a As will be seen from Figures 1- and 3the supporting plates 7 and 11 each have a flange12 by which they aresecured respectively toflanges, 1 3, and Hon the front of the flo'w'box.The slice dipsS and 6 are made ofrstainless steel and are secured to theweb-15 of their respectivesupporting plates by means ofbolts 16 andacarrier block 11 and the construction of the two supporting platesfland a slice lip itself and against which the slice-lip bears lfirmly dueto its inherent resilience; p l H Referring to Figures 3, 4 and15" itwill be seen that the supporting plate 7 has a plurality 'of pockets 19formed and, extending overits whole length. Ea ch of'these ordertochange the curvature of the lip. Since the flex iblebags or capsulesZS.will be smoothly curved'over the length of their pressureapplyingsurfaces a distributed pressure is applied to the, slice lip whichwilltherefore; be deformed in smooth curves across its length. By hav ing anappropriately large number of small bags for the length of slice lip amuchimproved control'of the. profile of the lip alongits length can beachieved.

In Figure 4 which shows a part only of the top and bottom slice] lips 5and 6 itgwill be noted'that one capsule 25 in-the bottom slicellip .6have been. subjected to increased pressure withthe result' that theslice lips 5' and are smoothly curved to produce a reduced spacing fromeach other in the region of those two'capsules'. i

Since with slices according to this invention no me; chanical means ofthe kind hithertoused are required for deforming the lip, it .will 'beappreciated that theflow'box' .can be disposed so that the slice feedsstraight into the .17. 'Along the inner surface at' the front edge ofeach supporting plate is a rib 18 which is directed towards the l Ineach pocket 19 thereis disposed a polyethylene bagf; or capsule 25offlat rectangular form each such capsule being connected to its fluidinlet pipe 24 centrally of the rear wall of the capsule. The bags orcapsules 25 are so 'clisposed in thepockets 19 that their largerr,ectangular surfacesabut respectively against the inner surface of thesupporting ing 9 ate 11 for the, bottom slice lip 6 is similar.

1 4 Each fluid. inlet pipe 24 passes via a connector 26 see plate 7 andtheouter surface of the actual The arrangement of capsules in; thesupportnip; of the top two 'wires. v

' Furthermore since the control of the lip profile is effected bypressure variation of the fluid in the bags,this can be carried out atany desired point remote from the flow boxto which the fiuidlines'can berun. Thus the and bottom wires of machines which use cumbersome-Vmechanical lip deforming mechanism on known flow boxes can be dispensedwith altogether. It; is

alsopossible to provide an. automatic control of the pro,- file of theslice lip by arranging for the signals from a substance gauging. deviceeg. of the beta ray type or from any otherjdetecting device whichdirectly or indirectly measures the thickness or substance of the paper,board" or other fibrous-material toefiectf the appropriate correstingpressure variations in the bags across the "slice.

It will be understood that we have only described indei tail onepreferred embodiment by way of example of the invention and'thatvariations and modifications may made therein-without departing fromitsscope. Thus for example-we may incorporate a pressure gauge in thefluid line :01 each "bag, which'will enablethe pressure applied 7 to thelip atdifferent par-ts of, itslength to be noted;

cure'diin thei body of the supporting plate and is individu ally nn tedea m asure c trdll ns lzel q 's 2.7 (Eis- It will-furtherrnore, beunderstood thatitis within zthe scope of this invention, to providemachines for making paper, board, forother fibrous products having asingle wire only or a top and. bottomewire and. incorporating, a

1. w qx. ha n w se a abqvesst c tli We c i i 1. A slice forthe flow boxof apaper or board in which said slice is provided with a top lip and abottom lip, one of said lips being'provided with at least one flexible,fluid impervious closed chamber device extending across its length andarranged to exert pressure on said lip, said closed chamber device beingadapted to be filled with fluid, and means for varying the fluidpressure in said closed chamber device in order to vary the profile ofthe lip. T

2. A slice as claimed in claim 1 inwhich said one lip has a singleflexible fluid impervious bag extending a substantial distancethereacross, said bag being of varying width over its length so thatvarying pressures can be applied to the lip over the length of the bag.

3. A slice as claimed in claim 1 in which said one lip is provided witha plurality of said closed chamber devices of substantially the sameshape and size extending there across.

4. A slice as claimed in claim 1 in which said closed chamber devicecomprises a bag having side walls, one of which engages said lip, theremaining walls being thicker than said one side wall.

5. A slice as claimed in claim 1 in which said closed chamber device isa bag of rectangular shape.

6. A slice as claimed in claim 1 including a plurality of said closedchamber devices, each of said devices being connected to a separatesource of fluid pressure to form): the pressure of fluid in a closedsystem therewith whereby each device can be individually adjusted.

7. A slice as claimed in claim 6 including means for I applying a commonpressure variation to all of the said closed systems.

8. A slice as claimed in claim 6 in which said devices are filled with aliquid.

9. A slice as claimed in claim 1 including a fixed supporting plateadjacent said one lip, a pocket in said plate facing said lip, saidclosed chamber device being disposed in said pocket. 7

10. -A slice as claimed in claim 9 in which the forward edge of saidsuporting plate has a rib which normally bears on said lip.

References Cited in the file of this patent UNITED STATES PATENTSl,632,760

